Improvement in machines for grinding the sectors of circles



e. RICHARDS. Machines for Grinding the Sector of Circles.

No. 222,736. Patented Dec 16, I879.

rat a s Unrrnn GEORGE RICHARDS, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNORTO THE I; T @FFIGE.

BETTS MACHINE COMPANY, OF WILMINGTON, DELAWARE.

Specification forming part of Letters Patent No. 222,736, dated December16, 1879; application filed August 5, 1879.

To all whom it may concern:

Be it known that I, GEO. RICHARDS, of Philadelphia, in the county ofPhiladelphia and State of Pennsylvania, have invented certain new anduseful Improvements in Machines for Grinding the Sectors of Circles; andI do hereby declare the following to be a full, clear, and exactdescription of the invention, such as will enable others skilled in theart to which it appertains to make and use the same, reference being hadto the accompanying drawing, and to letters of reference marked thereon,which form a part of this specification.

The object of this invention is to provide a ready method and means forgrinding and giving to the edges of flat bars and other forms of metalused in the arts the contour of a circular arc, and it will be found tobe of great service in the manufacture of the various styles of gagesused by machinists for determining the diameters of the circularapertures and cylindrical parts of their work.

My invention consists in the employment of a frame carrying the blank tobe ground, to which blank a rocking or vibratory motion is imparted, incombination, with an abradingwheel operating on the blank, to whichwheel a reciprocating and rotary motion is imparted by suitablemechanism, as hereinafter more fully set forth.

The drawing represents aperspective view of the machine and a tool orgage called a fixed caliper. The heel, or that portion of the caliperwhich is used for determining the diameter of a circular aperture, isshown as being ground.

A represents the bed of the machine, from one end of which rises thehead-stock B, while at the opposite end is placed the tail-stock G,which may, if desired, be made movable toward or from the head-stock ina manner similar to that of the tail-stock of the common lathe.

Two movable centers, at and a, pass through the head and tailblocks,being secured at any desired point therein by the set-screws band b, or other suitable devices, Between these centers is held thearticle to be ground, the edge to be operated upon being placed parallelto the axis of the centers.

A shaft, D, provided at one end with a pulley or other suitable meansfor imparting rotation, and at the other with the crank D, is connectedby the pitman c with the removable jaw E, which is secured to one edgeof the article to be operated upon by the setscrew 0.

It will thus be apparent that rotation of the shaft D will produce asemi-rotative or vibratory motion in the article placed between thecenters.

Moving in guides at d on the bed A is the standard F, which carries upona suitable shaft the abrading-wheel G, to which a quick rotary motion isimparted by a belt from any suitable motor running upon the pulley e.

A reciprocating motion is imparted to the standard F, carrying theabrading-wheel G, and sliding in the grooves or ways d d, in thefollowing manner: f is a post securely attached at its lower end to thebed-plate A, and having at its upper end a bearing for the shaft 6,carrying at its inner end the crank It, pivoted to the pitman t theopposite end of the latter being pivoted to the standard F, carrying theabrading-wheel G.

g is a pulley on the crank-shaft 2', around which passes an endlessbelt, which also passes around another pulley 011 a shaft driven by anymotor, by means of which a rotary motion is imparted to the crank-shaftt, which, through the pitman V, will impart a reciprocatin g motion tothe standard F in the ways d d, and also to the abrading-wheel G.

By this arrangement the abrading-wheel has a rotary and reciprocatingmotion imparted to it as it operates upon the blank, while the vibratoryor rocking movement of the blank renders the grinding operation moreexpeditious, and insures a smooth dressing of the latter in diagonallines across its face.

Having thus described my invention, I claim as new, and desire to secureby Letters Patent of the United States, the following:

1. The frame A, having the head-stock B,

tail-stock 0,-guides d d, and centers 00 a, carrying the blank to beground, in combination with the removable jaw E, pitman 0, crank D, andabrading-Wheel G, having a reciprocating and rotary motion,substantially as described, and for the purpose set forth.

2. The removable jaw E, pitman 0, and crank, in combination with thehead-stock B, for the purpose of imparting 'motion to an articleoperated on, substantially as and for the purpose set forth.

In testimony that I claim the foregoing I have hereunto set my hand this17th day of 1 July, 1879.

GEO. RICHARDS. Witnesses:

EDWARD Burrs, ALFRED Brc'rrs.

